(1) Field of the Invention
The present invention relates to a method for bonding a ceramic to a metal. More particularly, the present invention relates to a method for bonding a ceramic to a metal, which is suitable for obtaining a bonded structure for which a high strength and a high air-tightness are required.
(2) Description of the Prior Art
The conventional method for bonding a ceramic such as alumina to a metal comprises disposing an O-ring formed of pure Al as the insert between alumina and the metal and heating the assembly at a temperature higher than the melting point of the insert under an elevated pressure, as disclosed in the specification of U.S. Pat. No. 4,037,027.
According to this conventional bonding method, a metal, the main desired property of which is a corrosion resistance, is bonded to alumina, and use of a metal having a small thermal expansion or attainment of a good air-tightness is not taken into consideration.